In Germany? To “prevent potential perpetrators of violence” from entering the country?

It’s far too late for that, I’m afraid. And since when does Germany have borders?

Germany to introduce some border checks during G7 summit – Germany says it will temporarily introduce some border controls as the country gets ready to host the Group of Seven summit later this month in the Bavarian Alps

“The controls are intended to prevent potential perpetrators of violence from entering German territory, the statement said, adding that ”travelers must therefore expect to be subject to checks during this period.”